The Galileo, by default, boots from a linux image that is stored on an on board SPI device. This allows it to work without anything being installed, which is great. However, there are some problems with booting from the SPI device:

The space on the SPI device is limited

The SPI device it is not writeable,

Which means, every change you make from the default will have to be done every time the system powers up.

Sketches loaded to the Galileo will not be perminant.

Every time you power on your Galileo, you will have to upload your sketch again.

The simple and easy solution to these problems is to boot from an SD card. In order to boot from the SD card you will need a few things: